Emails dont get sent. They get stuck in "to send" folder.

Hello. I’m having a problem with sending emails.
Whenever I send an email it doesn’t get sent, it just sits in a folder called somenthing like “to send” (I don’t know how it is called in english, I am running it in spanish)

Hi,
are you getting any error messages? In the first place please use the Diagnose/Fix button in the account settings under the tab Diagnostics. Then inform me of the result. Thank you.

Thank you very much for taking the time to answer.
Apparently I had to get a license, so I did, and now it’s working fine.
I’m sorry for the trouble.

OK, thank you for the info.